The supex curved roof rafters are suitable for most caravans and RV’s with roll-out awnings, Curved roof rafters are ideal for keeping the vinyl on your awning from sagging and preventing water from pooling as well as keeping the fabric tight. Made from Stainless Steel and Glass Filled Nylon molded rail end which inserts into the bracket provided. This drastically increases the strength of the rafter while also reducing noise in windy conditions.